The foundation is the most important building structure, responsible for the safety and durability of the entire structure. The construction of the base requires almost a third of all the money allotted for the construction of the house, and private developers often use bricks to reduce costs. If you decide to build a foundation from brick, consider some of the nuances: a special construction technique, a variety of types of brick foundations, and features of soils. In order to build a reliable and strong basis, you need to understand all these subtleties.
Soil features and the selection of a suitable type of foundation
As you know, even on the same terrain different types of soil can be combined, such as:
- Foamy soil.
- Soil with medium heaving.
- Non-porous.
Composition of the first type: small particles of sand, pebbles, clay and gravel. The level and composition of groundwater contributes to high soil moisture. When freezing, ice crystals appear between the particles, which causes its further increase in size - expansion. The finer the individual soil particles, the higher the degree of heaving and vice versa. The worst option for buildings, it takes a lot of work to lay the foundation.
The second and third types have larger composite particles, therefore, they are less prone to swelling, and the likelihood of seasonal deformation of the building is much less. The basis on such a soil can last up to 30 years.
The exact type of soil can only be determined in laboratory conditions, however, if this is not possible, you will have to be content with a speculative analysis.
After the soil type is determined, we can proceed to the choice of the optimal type of foundation:
- if the soil becomes very agitated, it will be necessary to build an in-depth foundation of the strip type, having a trench even deeper than the level of freezing of the soil;
- medium-grained soil allows you to make a columnar foundation;
- non-porous soil is the best place to build, you can restrict yourself to a shallow tape base.
The brick foundation is very stiff, of a low level of strength, poorly resists moisture and low temperatures. Based on the above features, the brick base is suitable only for dry and non-porous soil with low groundwater.
Pros and Cons of a Brick Base
The advantages of brick, as a material for the foundation, include:
- the ability to give the tape a design of any shape, without formwork;
- ease and speed of restoration of damaged masonry elements;
- the ability to build the foundation entirely with your own hands (due to the lack of bulky and heavy construction elements);
- the service life of such a foundation can reach 35-40 years (subject to proper erection and proper care).
In addition, it is also worth noting the disadvantages of the foundation erected from brick:
- limited application possibilities. Such material is durable only when laying on non-porous, dry soil. To establish a brick foundation on unstable, heaving soil, you will have to additionally reinforce the structure;
- the material is extremely hygroscopic, which allows moisture to freely penetrate into the structure, and this negatively affects the stability of the foundation base;
- even 40 years of functioning of the brick foundation is less than the concrete base can provide.
Which brick is best used for the foundation?
Before buying materials for the construction of the foundation, you should make a note that hollow and silicate bricks should not be taken in any case. An ideal option for foundation masonry would be a well-fired, solid red ceramic brick. In contrast to hollow and silicate, this brick is resistant to moisture and less prone to seasonal deformations.
In addition, you should pay attention to the brand of material, namely, the load parameters per 1 square. cm (M) and frost resistance (F). Frost resistance should have a value from 35 to 100, and the degree of load should correspond to such brick grades as: M150, M175, M250, and M300.
Material base and tools
In order to build a brick foundation you will need the following materials:
- bricks;
- insulation and waterproofing materials;
- cement mortar;
- reinforcing mesh.
In addition, the following tools will be needed to build the foundation:
- tanks for cement mortar and shovels;
- Master OK;
- level and tape measure;
- hammer, mallet;
- knife;
- stakes and artificial cord.
Strip foundation
The construction of a strip foundation of brick is easy to do with your own hands. The entire construction process consists of the following steps:
- markup;
- land management;
- base filling;
- bricklaying.
Markup
In order to mark the site, it is necessary to install stakes in the supposed corners of the future building, pull a rope between them and check the level of the future site along the resulting contour.
After marking and leveling the site (if necessary), you can proceed with the excavation of the trench. The parameters of the trench should be thought out in advance in the drawing. The excavated soil is poured on both sides of the trench so that after the completion of all work it is seamless to fill up the finished strip foundation.
Foundation preparation
Now you can start laying the foundation, namely pillows made of sand and concrete. To do this, lay a layer of sand in 10-20 cm and compact it tightly. A hydroinsulator (polymer or roofing material) lays on top of the compacted sand layer. To prevent water from flowing into the foundation, it is necessary to bend the insulating material from all sides and only after that lay the concrete sole.
Brick laying and reinforcement
The next step is laying bricks and reinforcing. The main thing at this stage is to allow the brickwork to settle well and dry, which takes from 2 weeks to a month. In order to thicken the seam and prevent rotting of reinforcing bars, it is necessary to hide the reinforcement under the cement mortar by at least 0.5 cm.
In order for the foundation to better resist the effects of moisture, it is worth doing a beating along the perimeter of the entire base (concreting the soil). In this case, it is better to make a slight slope away from the foundation, so that the water drains without stagnation.
Column base
A brick pillar foundation is built as easily as a strip foundation.
The following stages of its construction can be distinguished:
- Land marking.
- Earthwork: digging a hole under each pillar of the structure (it is important to make holes exactly in accordance with the drawing and marking) and holes for the foundation.
- Preparing the basics. A 10-15-centimeter layer of crushed stone and sand is laid at the bottom of the pit and carefully rammed.
- If you are installing a columnar foundation of brick with your own hands, do not forget to mount the reinforcing mesh in order to strengthen the basis.
- Pouring concrete base over reinforcement.
- Laying bricks. Most often, about 4 bricks are laid in one row of a pillar. After laying, each of the pillars should protrude at least 20 centimeters over the edge of the trench. If the building plot is inclined, all poles must be aligned at the highest edge. Masonry is done in half a brick. The square columns resulting from this masonry have wastelands in the center, which are poured with concrete and additionally reinforced.Between the supports, sand or gravel is poured into the columnar foundation of brick, which improves the building's resistance to seasonal soil movements.
- After the concrete dries, you can proceed to the final stage - waterproofing the posts, for this the supports themselves are lubricated with mastic, and their outer part is covered with roofing material.
So, it doesn’t matter if you decided to erect a columnar foundation or a strip foundation: the main thing is to properly equip it. The correct bookmark is the key to durability and resistance to deformation.